Projection video display apparatus and video display method therefor

Abstract

A projection video display apparatus and method for solving a problem of deterioration of visibility of video that is projected on a transparent or semi-transparent screen. In a projection video display method for projecting and displaying video light on a rear surface or front surface of a transparent or semi-transparent video projection screen disposed in a space by a projection video display apparatus, video light to be projected and displayed is generated, the generated video light is projected on the rear surface or front surface of the transparent or semi-transparent video projection screen, and at that time, a video display position recognition screen for making an observer of the video recognize a position where the video is projected is projected on the transparent or semi-transparent video projection screen before start of the projection of the video light or simultaneously with the start of the projection of the video light.

The invention claimed is: 
     
       1. A projection video display apparatus for projecting and displaying video light on a rear surface or front surface of a transparent or semi-transparent video projection screen, the projection video display apparatus comprising:
 a light source which generates the video light to be projected and displayed; and 
 an optical system which projects the generated video light to the rear surface or front surface of the transparent or semi-transparent video projection screen, 
 wherein the optical system projects a screen position recognition information for enabling a user to recognize a position of the transparent or semi-transparent video projection screen where the generated video light is projected, and 
 wherein the screen position recognition information is projected and displayed before the generated video light is projected on the transparent or semi-transparent video projection screen or the screen position recognition information is projected and displayed during an initial period of a period when the generated video light is displayed on the transparent or semi-transparent video projection screen. 
 
     
     
       2. The projection video display apparatus according to  claim 1 ,
 wherein the screen position recognition information includes a portion which can be easily visually recognized in all or a part of a display screen projected and displayed on the rear surface or front surface of the transparent or semi-transparent video projection screen. 
 
     
     
       3. The projection video display apparatus according to  claim 2 ,
 wherein the portion of the screen position recognition information is displayed with colored light having a wavelength with a high luminosity function. 
 
     
     
       4. The projection video display apparatus according to  claim 3 ,
 wherein the portion of the screen position recognition information is displayed with green colored light. 
 
     
     
       5. The projection video display apparatus according to  claim 3 ,
 wherein the portion of the screen position recognition information is displayed with yellow colored light. 
 
     
     
       6. The projection video display apparatus according to  claim 3 ,
 wherein the portion of the screen position recognition information is displayed with orange colored light. 
 
     
     
       7. The projection video display apparatus according to  claim 2 ,
 wherein the portion of the screen position recognition information is displayed with a flashing light. 
 
     
     
       8. A video display method for projecting and displaying video light on a rear surface or front surface of a transparent or semi-transparent video projection screen by a projection video display apparatus including a light source which generates video light to be projected and displayed and an optical system to project the generated video light on the rear surface or front surface of the transparent or semi-transparent video projection screen, the method comprising the steps of:
 generating the video light; and 
 projecting a screen position recognition information for enabling a user to recognize a position of the transparent or semi-transparent video projection screen to be projected with the video light on the transparent or semi-transparent video projection screen before start of the projection of the generated video light or simultaneously with the start of the projection of the generated video light. 
 
     
     
       9. The video display method according to  claim 8 ,
 wherein the screen position recognition information is displayed on all or a part of a display screen of the transparent or semi-transparent video projection screen by an easily visually recognizable method. 
 
     
     
       10. The video display method according to  claim 9 ,
 wherein the screen position recognition information is displayed with colored light having a wavelength with a high luminosity function. 
 
     
     
       11. The video display method according to  claim 10 ,
 wherein the screen position recognition information is displayed with one or a plurality of colored lights selected from green colored light, yellow colored light, and orange colored light. 
 
     
     
       12. The projection video display apparatus according to  claim 1 , wherein the optical system is a scanning mirror. 
     
     
       13. The projection video display apparatus according to  claim 1 , wherein the light source generates a laser beam. 
     
     
       14. The projection video display apparatus according to  claim 12 , wherein the light source generates a laser beam. 
     
     
       15. The video display method according to  claim 8 , wherein the optical system is a scanning mirror. 
     
     
       16. The video display method according to  claim 8 , wherein the light source generates a laser beam. 
     
     
       17. The video display method according to  claim 15 , wherein the light source generates a laser beam.